Facebook - is it possible to like the cover photo of someone who is not your friend?

[Hiyahoo]

so i got a friend request from my ex who i am still not ready to accept among my facebook friends. i have his request pending. when i was viewing his profile in my tablet and i was browsing through his cover photos, there was one particular photo i liked a lot. (he's into nature photography i guess) and i had the options to like and comment when i viewed it in my tab. but these options are not available in my pc, so i am afraid if i like that cover photo he may be able to see my photos too, which i dont want to... should i like his photo?? i have told him i cannot accept his friend request but we are in good terms and i want to make him happy by appreciating his photo. advice please..